Re: Assistance with Star Wars w/Clay's ESB Kit --- SW novram clobber?

From: Altan (GAPAS) <pinball_at_aaarfamily.com>
Date: Mon Feb 21 2011 - 23:46:39 EST

Joel, you have it correct.

SW saves fine.
ESB saves fine.
Switch from ESB to SW (with power off) and SW loses settings

... Altan

On Feb 21, 2011, at 11:40 PM, Joel Rosenzweig wrote:

> If the timing was wrong, wouldn't it fail to save the score in that 2212 all the time? I thought he said that SW saved the scores now, but, when switching back from ESB, SW was re-initialized.
>
> Maybe I'm misreading him again.. don't know.
>
> Joel
>
>
>
> On Feb 21, 2011, at 11:33 PM, Jess Askey wrote:
>
>> I did lots of fanagling with the NVRAM on my I,Robot when it had trouble saving settings and indeed, Atari seemed to balance the /SAVE line with the timing of the +5V NVRAM supply *just right* to make the NVRAM save data right before power disappeared. Technically, if you doubled the load, the power supply would drop in about half the time so putting a big cap in parallel with C93 seems like the best bet... at least to eliminate that possibility.
>>
>> On 2/21/2011 8:42 PM, Clay Cowgill wrote:
>>>> I'm assuming this is the 2212 used for SW novram. Is that right?
>>> I'm 99% sure that's right. (Sorry, it's been a long time since I had to
>>> look at/think about that. ;-)
>>>
>>> The idea was that you could take your existing Star Wars settings and high
>>> scores and move them over to the daughterboard without losing anything.
>>>
>>> The only thing that comes to (my) mind at the moment is that maybe with two
>>> NOVRAMs sharing their connections (except for the chip select which is muxed
>>> by the game select switch) maybe the 'new' SW 2212 doesn't have enough time
>>> to store the SRAM copy of the memory to the NV portion of the chip before
>>> the EAROM power goes away.
>>>
>>> For grins, you might try something like putting a big electrolytic cap
>>> across the "+5EAROM" power and ground pins of the 2212's on the
>>> daughterboard. (Like a 470-1000uF or something-- you could also put it in
>>> parallel with C93 on the SW board-- careful with the polarity.)
>>>
>>> -Clay
>>>
>>> P.S. My apologies to anyone contacting me in the last few months if I
>>> missed replying to you. We *just* finished getting Ground Kontrol back to
>>> our permanent location after a huge three month remodel, so it'll be several
>>> weeks still before I get my head above water again. We were doing 120+ hour
>>> weeks there towards the end. ;-)
>>>
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Received on Mon Feb 21 23:46:43 2011

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